Question

Gopal sweets placed an order of making $30cm\times 20cm\times 6cm$ cardboard boxes for packing their sweets. For all overlaps, $4\%$ of total area is required extra. If cost of the cardboard is $25p$ for $100c{m}^2$, find the cost of the cardboard used for making $1000$ boxes.

Answer 1

Cardboard Required to make 1 box

Surface Area $=2\times (30\times 20)+2\times (20\times 6)+2\times (30\times 6)+\left(4\%ofTotalSurfaceArea\right)=1200+240+360+\frac{4}{100}\times (1200+240+360)=1800+72=1872c{m}^2$

Total card board $1872\times 1000=1872000c{m}^2$

Now for $100c{m}^2\to 25paisa=\frac{1}{4}rupee$

So, Total money $=1872000\times \frac{1}{4}\times \frac{1}{100}=4680rupees$